diff --git a/app/components/model-types/ModelTypeForm.vue b/app/components/model-types/ModelTypeForm.vue
index a0238eb..83c365c 100644
--- a/app/components/model-types/ModelTypeForm.vue
+++ b/app/components/model-types/ModelTypeForm.vue
@@ -108,56 +108,12 @@
       </template>
     </section>
 
-    <section v-if="form.category === 'PIECE'" class="space-y-4">
-      <header>
-        <h3 class="text-lg font-semibold text-base-content">Génération de référence automatique</h3>
-        <p class="mt-1 text-sm text-base-content/70">
-          Définissez une formule pour générer automatiquement une référence technique à partir des champs personnalisés.
-          Utilisez <code class="bg-base-200 px-1 rounded">{'{'}nom_du_champ{'}'}</code> comme placeholder.
-        </p>
-      </header>
-
-      <div class="rounded-lg border border-base-300 p-4 space-y-4">
-        <div>
-          <label class="label" for="reference-formula">
-            <span class="label-text">Formule</span>
-          </label>
-          <input
-            id="reference-formula"
-            v-model.trim="form.referenceFormula"
-            type="text"
-            class="input input-bordered w-full font-mono"
-            placeholder="Ex: {serie}{diametre}{type}"
-            :disabled="isReadonly"
-          />
-          <p class="mt-1 text-xs text-base-content/60">
-            Laissez vide si ce type n'utilise pas de référence automatique.
-          </p>
-        </div>
-
-        <div>
-          <label class="label" for="required-fields">
-            <span class="label-text">Champs requis</span>
-          </label>
-          <input
-            id="required-fields"
-            v-model.trim="requiredFieldsInput"
-            type="text"
-            class="input input-bordered w-full"
-            placeholder="Ex: serie, diametre, type"
-            :disabled="isReadonly"
-          />
-          <p class="mt-1 text-xs text-base-content/60">
-            Noms des champs séparés par des virgules. Si un champ requis est vide, la référence ne sera pas générée.
-          </p>
-        </div>
-
-        <div v-if="form.referenceFormula" class="rounded bg-base-200 px-3 py-2 text-sm">
-          <span class="text-base-content/70">Aperçu :</span>
-          <span class="ml-1 font-mono font-semibold">{{ formulaPreview }}</span>
-        </div>
-      </div>
-    </section>
+    <ReferenceFormulaBuilder
+      v-if="form.category === 'PIECE' || form.category === 'COMPONENT'"
+      v-model="form.referenceFormula"
+      :custom-fields="formulaBuilderCustomFields"
+      :disabled="isReadonly"
+    />
 
     <footer class="flex flex-col gap-3 border-t border-base-300 pt-4 sm:flex-row sm:justify-end">
       <button type="button" class="btn btn-ghost" :disabled="saving" @click="emit('cancel')">
@@ -228,23 +184,33 @@ const componentSubcomponentMaxDepth = computed(() =>
 )
 const isReadonly = computed(() => props.readonly === true)
 
-const form = reactive<ModelTypePayload & { referenceFormula?: string | null; requiredFieldsForReference?: string[] | null }>({
+const form = reactive<ModelTypePayload & { referenceFormula?: string | null }>({
   name: '',
   code: '',
   category: props.initialCategory,
   notes: '',
   structure: undefined,
   referenceFormula: null,
-  requiredFieldsForReference: null,
 })
 
-const requiredFieldsInput = ref('')
-
-const formulaPreview = computed(() => {
-  if (!form.referenceFormula) return ''
-  return form.referenceFormula.replace(/\{(\w+)\}/g, '___')
+const formulaBuilderCustomFields = computed(() => {
+  if (form.category === 'PIECE') {
+    const fields = pieceStructure.value?.customFields
+    return Array.isArray(fields) ? fields : []
+  }
+  if (form.category === 'COMPONENT') {
+    const fields = componentStructure.value?.customFields
+    return Array.isArray(fields) ? fields : []
+  }
+  return []
 })
 
+const extractFormulaFields = (formula: string | null | undefined): string[] => {
+  if (!formula) return []
+  const matches = [...formula.matchAll(/\{(\w+)\}/g)]
+  return [...new Set(matches.map(m => m[1]).filter((n): n is string => n !== undefined))]
+}
+
 const errors = reactive<{ name?: string }>({})
 const nameInput = ref<HTMLInputElement | null>(null)
 
@@ -310,8 +276,6 @@ const resetForm = () => {
 
   const incomingAny = incoming as Record<string, unknown>
   form.referenceFormula = typeof incomingAny.referenceFormula === 'string' ? incomingAny.referenceFormula : null
-  form.requiredFieldsForReference = Array.isArray(incomingAny.requiredFieldsForReference) ? incomingAny.requiredFieldsForReference : null
-  requiredFieldsInput.value = form.requiredFieldsForReference?.join(', ') ?? ''
 
   resetStructures(incoming.structure, form.category)
 }
@@ -351,24 +315,27 @@ const handleSubmit = () => {
   }
 
   if (form.category === 'COMPONENT') {
+    const formula = form.referenceFormula || null
+    const requiredFields = extractFormulaFields(formula)
     emit('submit', {
       ...common,
       category: 'COMPONENT',
       structure: normalizeStructureForSave(cloneStructure(componentStructure.value)),
-    })
+      referenceFormula: formula,
+      requiredFieldsForReference: requiredFields.length ? requiredFields : null,
+    } as ModelTypePayload)
     return
   }
 
   if (form.category === 'PIECE') {
-    const parsedRequiredFields = requiredFieldsInput.value
-      ? requiredFieldsInput.value.split(',').map(s => s.trim()).filter(Boolean)
-      : null
+    const formula = form.referenceFormula || null
+    const requiredFields = extractFormulaFields(formula)
     emit('submit', {
       ...common,
       category: 'PIECE',
       structure: normalizePieceStructureForSave(clonePieceStructure(pieceStructure.value)),
-      referenceFormula: form.referenceFormula || null,
-      requiredFieldsForReference: parsedRequiredFields?.length ? parsedRequiredFields : null,
+      referenceFormula: formula,
+      requiredFieldsForReference: requiredFields.length ? requiredFields : null,
     } as ModelTypePayload)
     return
   }
diff --git a/app/components/model-types/ReferenceFormulaBuilder.vue b/app/components/model-types/ReferenceFormulaBuilder.vue
new file mode 100644
index 0000000..5587f68
--- /dev/null
+++ b/app/components/model-types/ReferenceFormulaBuilder.vue
@@ -0,0 +1,115 @@
+<template>
+  <section class="space-y-4">
+    <header>
+      <h3 class="text-lg font-semibold text-base-content">Génération de référence automatique</h3>
+      <p class="mt-1 text-sm text-base-content/70">
+        Cliquez sur un champ pour l'insérer dans la formule. Vous pouvez aussi taper du texte libre (séparateurs, préfixes…).
+      </p>
+    </header>
+
+    <div class="rounded-lg border border-base-300 p-4 space-y-4">
+      <div v-if="fieldNames.length" class="flex flex-wrap gap-2">
+        <button
+          v-for="name in fieldNames"
+          :key="name"
+          type="button"
+          class="btn btn-xs btn-outline btn-primary font-mono"
+          :disabled="disabled"
+          @click="insertField(name)"
+        >
+          {{ name }}
+        </button>
+      </div>
+      <p v-else class="text-sm text-base-content/50 italic">
+        Aucun champ personnalisé défini dans la structure.
+      </p>
+
+      <div>
+        <label class="label" for="reference-formula">
+          <span class="label-text">Formule</span>
+        </label>
+        <input
+          id="reference-formula"
+          ref="inputRef"
+          :value="modelValue"
+          type="text"
+          class="input input-bordered w-full font-mono"
+          placeholder="Ex: SNU {serie}-{diametre}/{type}"
+          :disabled="disabled"
+          @input="emit('update:modelValue', ($event.target as HTMLInputElement).value || null)"
+        />
+        <p class="mt-1 text-xs text-base-content/60">
+          Laissez vide si ce type n'utilise pas de référence automatique.
+        </p>
+      </div>
+
+      <div v-if="modelValue" class="rounded bg-base-200 px-3 py-2 text-sm">
+        <span class="text-base-content/70">Aperçu :</span>
+        <span class="ml-1 font-mono font-semibold">{{ preview }}</span>
+      </div>
+    </div>
+  </section>
+</template>
+
+<script setup lang="ts">
+import { computed, nextTick, ref } from 'vue'
+
+interface CustomField {
+  name: string
+  type: string
+}
+
+const props = defineProps<{
+  modelValue: string | null | undefined
+  customFields: CustomField[]
+  disabled?: boolean
+}>()
+
+const emit = defineEmits<{
+  (e: 'update:modelValue', value: string | null): void
+}>()
+
+const inputRef = ref<HTMLInputElement | null>(null)
+
+const fieldNames = computed(() =>
+  props.customFields.map(f => f.name).filter((n): n is string => Boolean(n)),
+)
+
+const previewExamples: Record<string, string> = {
+  text: 'VALEUR',
+  number: '123',
+  select: 'OPTION',
+  boolean: 'OUI',
+  date: '2026-01-01',
+}
+
+const preview = computed(() => {
+  if (!props.modelValue) return ''
+  const fieldMap = new Map<string, string>()
+  for (const f of props.customFields) {
+    if (f.name) {
+      fieldMap.set(f.name, previewExamples[f.type] ?? 'VALEUR')
+    }
+  }
+  return props.modelValue.replace(/\{(\w+)\}/g, (_, name) => fieldMap.get(name) ?? '???')
+})
+
+const insertField = (fieldName: string) => {
+  const placeholder = `{${fieldName}}`
+  const input = inputRef.value
+  const current = props.modelValue ?? ''
+  if (!input) {
+    emit('update:modelValue', current + placeholder)
+    return
+  }
+  const start = input.selectionStart ?? current.length
+  const end = input.selectionEnd ?? start
+  const updated = current.slice(0, start) + placeholder + current.slice(end)
+  emit('update:modelValue', updated)
+  nextTick(() => {
+    const newPos = start + placeholder.length
+    input.focus()
+    input.setSelectionRange(newPos, newPos)
+  })
+}
+</script>
diff --git a/app/pages/changelog.vue b/app/pages/changelog.vue
index 6b00039..3fed311 100644
--- a/app/pages/changelog.vue
+++ b/app/pages/changelog.vue
@@ -72,6 +72,28 @@ const badgeClass = (type: ChangeType) => {
 };
 
 const releases: Release[] = [
+    {
+        version: "v1.9.5",
+        date: "2026-03-31",
+        changes: [
+            {
+                type: "feat",
+                text: "Référence automatique des pièces et composants : génération d'une référence technique à partir d'une formule configurable sur la catégorie, recalculée automatiquement à chaque modification des champs personnalisés",
+            },
+            {
+                type: "feat",
+                text: "Formula builder interactif : sélection des champs disponibles par clic (chips) avec insertion à la position du curseur, aperçu live avec valeurs d'exemple, et calcul automatique des champs requis",
+            },
+            {
+                type: "feat",
+                text: "Versioning des entités : numéro de version incrémenté automatiquement à chaque modification, avec historique des versions et possibilité de restaurer une version antérieure",
+            },
+            {
+                type: "feat",
+                text: "Bouton de sauvegarde unique sur la fiche machine : remplacement des sauvegardes automatiques par un bouton explicite, avec affichage des versions sur les liens composants/pièces/produits",
+            },
+        ],
+    },
     {
         version: "v1.9.4",
         date: "2026-03-25",
diff --git a/app/pages/component-category/[id]/edit.vue b/app/pages/component-category/[id]/edit.vue
index d9a7f2d..c1b9a56 100644
--- a/app/pages/component-category/[id]/edit.vue
+++ b/app/pages/component-category/[id]/edit.vue
@@ -114,6 +114,8 @@ const loadCategory = async () => {
       category: response.category,
       notes: response.notes ?? response.description ?? '',
       structure: (response.structure as ComponentModelStructure | null) ?? undefined,
+      referenceFormula: response.referenceFormula ?? null,
+      requiredFieldsForReference: response.requiredFieldsForReference ?? null,
     }
 
   } catch (error) {
diff --git a/app/services/modelTypes.ts b/app/services/modelTypes.ts
index 99efb6b..d072959 100644
--- a/app/services/modelTypes.ts
+++ b/app/services/modelTypes.ts
@@ -23,6 +23,8 @@ export interface BaseModelTypePayload {
 export interface ComponentModelTypePayload extends BaseModelTypePayload {
   category: 'COMPONENT';
   structure?: ComponentModelStructure | null;
+  referenceFormula?: string | null;
+  requiredFieldsForReference?: string[] | null;
 }
 
 export interface PieceModelTypePayload extends BaseModelTypePayload {